This invention relates to a new and distinct perennial variety of St. Augustinegrass that is well-suited for turfgrass applications. It is a high-quality, high-density cultivar well-adapted for warm weather climates similar to that found in southern climates where high quality St. Augustinegrass grass cultivar varieties have previously not been available. The Latin name of the genus and species of the new cultivar disclosed herein is Stenotaphrum secundatum. This novel hybrid genotype has been given the varietal denomination ‘MSA-31’ and is a perennial, asexually propagated genotype of St. Augustinegrass, which typically grows vigorously well in warm weather climates and spreads through creeping stolons that root at the nodes contacting soil with adequate moisture. Commonly-known varieties of this genus and species include Raleigh St. Augustine (not patented), ‘Floratam’ (not patented), B12 (U.S. Plant Pat. No. 16,174 and marketed under the tradename ‘Sapphire’™), and SS-100 (U.S. Plant Pat. No. 9,395 and marketed under the tradename ‘Palmetto’™). This high quality novel and distinct variety of St. Augustinegrass was first vegetatively propagated at Starkville, Miss. using stolon cuttings and asexually propagated from the time forward to maintain a single genotype.